Taken at face value (a dubious assumption), this WaPo look at one teacher's IMPACT observation suggests that the process is more subtle and focused on details of instruction and learning than I would have thought. This is potentially a good thing.
On the other hand, this cuts against the larger "we're just getting rid of bad teachers" messaging. You know, the person standing in the doorway turning their lights on and off in a vain attempt to get the kid's attention. The porn-surfer. The clock-watcher. The people who should not be teachers.
I always felt like teachers like the one portrayed in the article -- who understand and relate to their students, who are past the basics of classroom management, who are committed to teaching over the long haul, but are pedagogically not very sophisticated -- are the key test for urban school administration and professional development. In the long run, you have to be able to reach those people, they have to be your foundation, or you are screwed.
The idea that you're going to fix your school system by laying these people off first, is, like Russo says, "particularly goofy." As is the idea that giving these folks financial incentives will improve their instruction. Or for that matter, that you'd be better off training a whole sequence of brainy kids instead of one dedicated teacher.